The invention concerns a linear guidance system comprising a guide rail and a carriage which is guided displaceably on the guide rail by way of at least two ball bearings, wherein the ball bearings respectively comprise a plurality of balls and a ball cage and the guide rail has running surfaces and the carriage has running surfaces for the rolling movement of the balls of the ball bearings.
Linear guidance systems can be used in the most widely varying areas. Automobile engineering involves the use of linear guidance systems with a high load-bearing capacity inter alia for vehicle sliding doors, load floor pans, variable-length consoles in the vehicle interior and other devices.
In the area of vehicle sliding doors, for reasons of stability guide rails on which the sliding doors are guided are frequently mounted at the outside of the bodywork. Such mounting at the outside of the bodywork admittedly ensures a high stability for the guidance system under the loading of the weight of the sliding door, but the guide rails mounted on the outside of the bodywork are visible when the sliding door is closed and considerably spoil visual appearance. In addition, by virtue of being fitted on the outside of the vehicle, those guide rails are constantly exposed to external weather conditions and therefore corrode more rapidly than internally mounted guidance systems or require a considerably higher level of corrosion protection. In addition such guide rails are profiled so that dirt out of the environment rapidly accumulates at and in the rails and that very rapidly causes a deterioration in the running properties of the guidance system.
A sliding door for motor vehicles having a guide rail mounted on the inside of the door, in which some of the aforementioned disadvantages of guide rails mounted on the outside of the bodywork are overcome is disclosed in DE 43 14 115 A1. The described guidance system for a motor vehicle sliding door however does not have particularly good running properties and thus does not have a good feel and is comparatively noisy.
The object of the present invention was that of providing a linear guidance system which can carry high loads, which involves the production of a low level of noise, which is of a compact structure, which permits long displacement travel movements and which is comparatively inexpensive to produce. A further object of the invention was that of providing a linear guidance system for vehicle sliding doors, load floor pans, variable-length consoles in the vehicle interior etc, having the aforementioned properties.